Proton exchange membrane fuel cells (PEMFCs) generate power from electrochemical conversion of fuels, such as hydrogen and hydrocarbons, at their anodes and oxidants, such as oxygen and air, at their cathodes using the polymer membrane as electrolyte. The membrane acts both as a proton conductor from anode to cathode and a barrier between fuels and oxidants. Current state-of-art membranes such as Nafion™ membranes, Aquivion™ membranes, and low equivalent weight (EW) perfluorosulfonic acid (PFSA) membranes have only one sulfonic acid group in the side chain. As a result, these membranes hold little water at any given relative humidity (RH %) and have very low ionic conductivity, especially at low RH % and at temperatures below 100° C.